Sublimation from a Seasonal Snowpack
at a Continental, Mid-Latitude Alpine Site
Eran W. Hood1, Mark W. Williams1, and Don Cline2
Sublimation from the seasonal snowpack was calculated using the aerodynamic profile method at
Niwot Ridge in the Colorado Front Range. Past studies of sublimation from snow have been incon-
clusive in determining both the rate and timing of the transfer of water between the snowpack and the
atmosphere, primarily because they relied on one-dimensional measurements of turbulent fluxes or
short-term data sets. We calculated latent heat fluxes at ten-minute intervals based on measurements
of temperature, relative humidity, and wind speed at heights of 0.5 m, 1.0 m, and 2.0 m above the
snowpack for nine months during the 199495 snow season. The meteorological instruments were
raised or lowered daily to maintain a constant height above the snow surface. At each ten-minute
time step, the latent heat fluxes were converted directly into millimeters of sublimation or condensa-
tion. Total net sublimation for the snow season was 195 mm of water equivalent, or 15% of maxi-
mum snow accumulation at the study site. The majority of this sublimation occurred during the snow
accumulation season. Monthly losses to sublimation during the fall and winter ranged from 27 to 54
mm of water equivalent. The snowmelt season from May through mid-July showed net condensation
to the snowpack ranging from 5 to 16 mm of water equivalent. Sublimation was sometimes episodic
in nature, but often showed a diurnal periodicity with higher rates of sublimation during the day.
1
Department of Geography and Institute of Arctic and Alpine Research, University of Colorado, Boulder,
Colorado 80302, USA
2 National Hydrologic Remote Sensing Center, National Weather Service, Chanhassen, Minnesota 55317,
USA
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